Carotid artery calcification detected on panoramic radiographs in a group of Thai population Suchaya Pornprasertsuk-Damrongsri, DDS, MS, PhD, a and Supanee Thanakun, DDS, MS, b Bangkok, Thailand MAHIDOL UNIVERSITY FACULTY OF DENTISTRY Objective. To determine the prevalence of carotid artery calcification (CAC) detected on panoramic radiographs in a Thai population. Study design. The panoramic radiographs of the patients 50 and older (N = 1,370) visiting Mahidol University from January 1998 through September 2004 were retrospectively reviewed for CAC. The medical records of the positive subjects were then reviewed. Results. Thirty-four (2.5%) of the 1,370 patients, 16 men and 18 women, with a mean age of 69 and a range of 50 to 87 years, had 1 or more CACs. These calcifications were unilateral in 25 (73.5%) and bilateral in 9 (26.5%) subjects. Of those positive subjects, 18 reported hypertension, 10 reported diabetes mellitus, and 5 reported hyperlipidemia. Conclusions. Although it is uncommon to find CAC in the Thai population, dentists should be aware of this calcification on the routine panoramic radiographs and promptly refer for cerebrovascular and cardiovascular evaluation. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101:110-5) Stroke is one of the most common diseases leading to disability or death in Thailand. 1 Several risk factors for stroke are classified into nonmodifiable and modifi- able factors. The former are age, gender, ethnicity, and heredity, and the latter are hypertension, diabetes mellitus, hyperlipidemia, obesity, smoking, and carotid atherosclerotic disease. 2 Early detection of these risk factors reduces the morbidity and mortality. In 1981, Friedlander and Lande suggested that panoramic radio- graph is a useful aid in detecting patients at risk of stroke, because the carotid artery calcification (CAC) may be seen in the lower corners of the panoramic radiograph adjacent to the cervical vertebrae at the level of the C3-C4 intervertebral junction. 3 Such calcifica- tion may appear as either a nodular radiopaque mass or radiopaque vertical lines inferior to the angle of mandible. 3 Carotid atherosclerosis is not the only cause of cervical calcification seen anterior to the cervical vertebrae in panoramic radiographs. Dentists must be careful to differentiate CACs from anatomic structures including calcified triticeous or thyroid cartilages, hyoid bone, calcified stylohyoid ligament, and epiglottis and from pathologic conditions such as calcified lymph nodes, phleboliths, submandibular salivary gland sialo- liths, and tonsilloliths. 4,5 The purpose of this paper was to determine retro- spectively the presence of CAC detected on routine panoramic dental radiographs in a Thai population. MATERIALS AND METHODS From January 1, 1998, through September 30, 2004, all panoramic radiographs used as a part of dental care on patients 50 years of age and older at the Faculty of Dentistry, Mahidol University, Thailand, were retro- spectively reviewed for the presence of CAC. All radiographs were taken using either the ortho- pantomograph-OP100 (Instrumentarium Imaging, Tuusula, Finland), the Planmeca PM2002CC (Planmeca Oy, Helsinki, Finland), or the Orthoralix (Philips Med- ical Systems, Monza, Italy) panoramic x-ray systems and Kodak dental film (T-MAT G; Eastman Kodak, Rochester, NY) with Kodak Lanex regular intensifying screen. The exposed films were processed with a Kodak X-OMAT 2000 automatic film processor according to the manufacturer’s recommendations. The radiographs were examined by an oral and maxillofacial radiologist (SP) in subdued ambient light using transmitted light from a standard viewing box for the presence of the CACs appearing as an irregular, heterogeneous, vertico- linear, or circular radiopaque mass inferior to the angle of the mandible and adjacent to the cervical vertebrae at the level of the C3-C4 intervertebral junction. Other cervical calcifications, including calcified triticeous cartilage, hyoid bone, superior horn of thyroid cartilage, calcified lymph nodes, phleboliths, and submandibular a Instructor, Department of Oral Radiology. b Assistant Professor, Department of Oral Medicine. Received for publication Nov 3, 2004; returned for revision Apr 7, 2005; accepted for publication Apr 9, 2005. 1079-2104/$ - see front matter Ó 2006 Mosby, Inc. All rights reserved. doi:10.1016/j.tripleo.2005.04.002 110